Respiratory-related death in individuals with incident asthma and COPD: a competing risk analysis.

BACKGROUND: Distinguishing between mortality attributed to respiratory causes and other causes among people with asthma, COPD, and asthma-COPD overlap (ACO) is important. This study used electronic health records in England to estimate excess risk of death from respiratory-related causes after accounting for other causes of death. METHODS: We used linked Clinical Practice Research Datalink (CPRD) primary care and Office for National Statistics mortality data to identify adults with asthma and COPD from 2005 to 2015. Causes of death were ascertained using death certificates. Hazard ratios (HR) and excess risk of death were estimated using Fine-Gray competing risk models and adjusting for age, sex, smoking status, body mass index and socioeconomic status. RESULTS: 65,021 people with asthma and 45,649 with COPD in the CPRD dataset were frequency matched 5:1 with people without the disease on age, sex and general practice. Only 14 in 100,000 people with asthma are predicted to experience a respiratory-related death up to 10 years post-diagnosis, whereas in COPD this is 98 in 100,000. Asthma is associated with an 0.01% excess incidence of respiratory related mortality whereas COPD is associated with an 0.07% excess. Among people with asthma-COPD overlap (N = 22,145) we observed an increased risk of respiratory-related death compared to those with asthma alone (HR = 1.30; 95% CI 1.21-1.40) but not COPD alone (HR = 0.89; 95% CI 0.83-0.94). CONCLUSIONS: Asthma and COPD are associated with an increased risk of respiratory-related death after accounting for other causes; however, diagnosis of COPD carries a much higher probability. ACO is associated with a lower risk compared to COPD alone but higher risk compared to asthma alone.

Changing causes of death for patients with chronic respiratory disease in England, 2005-2015.

BACKGROUND: Chronic respiratory diseases (CRD) are common, are increasing in prevalence, and cause significant morbidity and mortality worldwide. However, we have limited knowledge on causes of death of patients with CRD in the general population. OBJECTIVE: We evaluated mortality rates and causes of death over time in patients with CRD. METHODS: We used linked primary care and mortality data to determine mortality rates and the most common causes of death in people with CRD (including asthma, bronchiectasis, COPD and interstitial lung diseases (ILD)) during 2005-2015 in England. RESULTS: We identified 558 888 patients with CRD (451 830 asthma, 137 709 COPD, 19 374 bronchiectasis, 10 745 ILD). The age-standardised mortality rate of patients with CRD was 1607 per 100 000 persons (asthma=856, COPD=1503, ILD=2609, bronchiectasis=1463). CRD mortality was overall 54% higher than the general population. A third of patients with CRD died from respiratory-related causes. Respiratory-related mortality was constant, while cardiovascular-related mortality decreased significantly over time. COPD accounted for the majority of respiratory-related deaths (66% overall) in all patient groups except ILD. CONCLUSIONS: Patients with CRD continue to experience substantial morbidity and mortality due to respiratory diseases. Disease-modifying intervention strategies are needed to improve outcomes for patients with CRD.

Understanding the relationships between environmental factors and exacerbations of COPD.

INTRODUCTION: Exacerbations of chronic obstructive pulmonary disease (COPD) are associated with a significant health burden both for patients and healthcare systems. Exposure to various environmental factors increases the risk of exacerbations. AREAS COVERED: We searched PubMed and assessed literature published within the last 10 years to include epidemiological evidence on the relationships between air pollution, temperature and COPD exacerbation risk as well as the implications of extreme weather events on exacerbations. EXPERT OPINION: Ongoing climate change is expected to increase air pollution levels, global temperature and the frequency and severity of extreme weather events, all of which are associated with COPD exacerbations. Further research is needed using patient-focused methodological approaches to better understand and quantify these relationships, so that effective mitigation strategies that decrease the risk of exacerbations can be developed.